This thesis deals with the wear of indexable insert during machining railway axles in BONATRAS GROUP Inc. Thesis describes the technological process of this company and basic types of wear inserts. It also assesses the development of tool wear when cutting speed is increase by 10% and also to compare the wear inserts from different suppliers for that company. This work mainly deals with development of ridge wear of the cutting tool depending on the pressure of coolant.

The diploma thesis is focused on the study of pressure-induced changes in a behavior of RECo2-type compounds. HoCo2 and its substitution of Si instead of Co in Ho(Co1-xSix)2, x = 0,025 were chosen as a representative compounds from this family of materials. Measurements of electric resistivity, heat capacity, magnetization and AC magnetic susceptibility under ambient pressure showed presence of three magnetic transitions for both samples: the change of the easy magnetization direction at TR ~ 16 K, the Curie temperature TC ~ 80 K and the flipping of magnetization of Co magnetic moments into the parallel direction with Ho magnetic moments at Tf ~ 125 K for HoCo2. Under hydrostatic pressures up to 3 GPa, the TR shifts to higher temperatures whereas TC and Tf, both decrease. This probably occurs due to the weakening of the Co magnetism and the strength of exchange interaction between Ho-Co sublattices. The experiment of muon spin rotation demonstrates a pressure influence to the decay of Co magnetic clusters, which occurs at lower temperatures with increasing pressure. It is evident that the hydrostatic pressure directly influences the exchange interaction between Co-Co.

This diploma thesis is focused on the study of the structural phase transitions in intermetallic compounds LaPd2(Al,Ga)2 by low-temperature x-ray powder diffraction and macroscopic measurements on single crystals. The results obtained from powder diffraction at room temperature confirm that the compounds crystallize in tetragonal CaBe2Ge2 structure type (space group P4/nmm). At low temperature all the compounds undergo the same structural phase transition by lowering the symmetry to the orthorhombic space group Cmma. Although the structural transformation is of first order, the transition is not-manifested in step-like change of the phase at a certain temperature, but occurs in a broader temperature interval. In this interval the different phases coexist and transform gradually from high- to low- temperature phase. After application of hydrostatic pressure the structural transition is shifted to higher temperatures. Despite that the low temperature structures are of the same type, there is a difference between compounds containing Ga and Al in the discontinuity of the lattice parameters resulting in a distinct anomaly in electrical resistivity. In pressures >0.6 GPa this characteristic anomaly on single crystalline CePd2Al2 is changed, indicating a pressure- induced change of the low-temperature...

Magnetic properties of RCo2 compounds have been studied since the sec- ond half of the last century. However, there was recently observed new mag- netic state, so-called parimagnetism. The aim of this thesis was to find the real behavior of TmCo2, which exhibits many discrepancies in the published results, by means of preparation of high-quality single-crystals, its characteri- zation around the ordering temperature and to study parimagnetic behavior. Obtained results showed differences between the samples, which should be caused by the instability of Co and Tm magnetism. It might be the reason of discrepancies in the literature. The results however show the same struc- ture of measured curves with two present phase transition. We suggest two possible interpretations: a) magnetic reorientation of Tm magnetic moments below the ordering temperature of the Tm sub-lattice or b) consequent or- dering of the rare-earth sub-lattice followed by ordering of the Co sub-lattice at lower temperature, which seems to be more realistic. We observed pari- magnetic anomalies at 38 K, 80 K, 168 K only in the case of single-crystals containing small amount of impurity phase, which probably affects the for- mation of magnetic clusters. 1

Title: Magnetism in the non-centrosymmetric uranium compound: UIrSi3 Author: RNDr. Jaroslav Valenta Department: Department of Condensed Matter Physics Supervisor of the doctoral thesis: RNDr. Jiří Prchal, Ph.D., DCMP Abstract: The study presented in this thesis is focused on UIrSi3 which is one of two known uranium compounds that crystallize in a non-centrosymmetric structure. This first study of UIrSi3 in single-crystalline form confirms antiferromagnetic order below TN = 41.7 K and reveals strong uniaxial anisotropy. The antiferromagnetic order is suppressed by application of a magnetic field along the c axis (0HC = 7.3 T at 2 K). In contrast, application of a magnetic field up to 14 T along the a axis gives paramagnetic response. The high TN, contrasting with the low 0HC, together with the opposite signs of the paramagnetic Curie temperatures of the a-axis and c-axis paramagnetic susceptibility indicate a competition between antiferromagnetic and ferromagnetic interactions. The first-order metamagnetic transition at HC shows asymmetric hysteresis which reflects a complex antiferromagnetic ground state. With increasing temperature, the hysteresis becomes gradually smaller and vanishes at 28 K where the first-order transition changes to second-order transition which remains up to TN. The point where the...

Presented thesis focuses on the study of transport properties of two intermetallic compounds, CeRhSi3 and CeCuAl3, under high external pressure. High-pressure dependence of previously reported pressure induced superconductivity in CeRhSi3 is studied closely up to 4.6 GPa, focusing on the, so-far-unstudied, pressure region above 3 GPa. After reaching maximal value at 2.9 GPa, the critical temperature of superconducting transition is gradually suppressed by further pressure application. Extensive search for possible pressure induced superconductivity in CeCuAl3 is conducted, employing solid-pressure-medium Bridgman anvil cells with theoretical pressure limit of 12 GPa. No pressure induced superconductivity is observed up to 4.5 GPa and down to 8 mK. Additionally, a calibration study of three liquid pressure exchange media from Daphne Oil 7000 series is carried out in order to advance high pressure experimental techniques. Comprehensive results about hydrostaticity, solidification, pressure drop and compressibility of individual pressure media are presented.

Title: Success rate of beach volleyball serves at the end of the sets and matches. Objective: The aim of the thesis is to find out a success rate of serves based on observing chosen factors at the end of the beach volleyball sets and matches. Methods: The research sample is represented by the Czech women's beach volleyball elite pair. There are observation and interview methods used in the thesis. The observation is expressed by filling information about serves into tables through stated scales. The interview is focused on player's feelings while serving and specific factors that influence players through the whole match. Results: The results were recorded into graphs and each of them has its own comment. The graphic results are complemented by interviews with players. Keywords: Serve, game performance, mental pressure, feelings, observation

Title: The effect of breathing technique on intra-thoracic pressure, kinematics of barbell, and muscle activity during bench press exercise. Objectives: The main aim of this study is to determine relationship between breathing technique and bench press exercise. Furthermore, determine which breathing modification leads to overcoming highest resistance and how each individual breathing techniques (Valsalva maneuver (VM), Hold breath (HB), Lung packing (PAC), "reversed breathing" (REVB)) affects kinematics of barbell, and muscle activity, during different intensity (1 RM, 4RM, 8RM, 12RM). Methods: Experiment of cross-sectional character, with usage of our-calibrated sensor, for intrathoracic pressure measurements, 3D kinematics with passive markers and surface electromyography. For measuring anthropometric measurements was further used goniometer, digital scale, and measuring tape. Comparisons of the breathing techniques was done by analysis of covariance ANOVA, while particular parameters were compared by Pearson correlation. Results: Except of REVB technique, which indicated significantly lower load, there was no significant difference between techniques in lifted resistance. Similar effect was observed at results of intrathoracic pressure, where REVB technique showed significantly lower pressure,...

The theoretical part of the diploma thesis describes the role of abdominal muscles in intra-abdominal pressure and the effect on postural stabilization. The issue of postural stabilization was analyzed in a physiological situation and frequent pathologies related with inadequate postural stabilization have been described. The current possibilities of evaluating the activity of abdominal muscles and intra-abdominal pressure were presented. Methodology: 25 healthy probands (mean age 22.4 years, SD ± 1.76) were evaluated in five posturally different situations - breathing stereotype test, intra-abdominal pressure regulation test, diaphragm test, hip flexion test and arm elevation test. Testing was performed with a prototype of the DNS Brace digital pressure sensor. The resulting pressure values of the abdominal wall expansion were correlated with the corresponding postural tests according to the DNS concept, which were performed by two DNS instructors with more than five years of experience. Results: A statistically significant correlation (p = 0.001 to 0.24) between abdominal wall pressure values and palpation-evaluated postural tests was demonstrated in four of the five tested positions. Correlation was strong in diaphragm test (r = 0.75 and 0.661) and mean in other tests (r = 0.567 to 0.415). Only...

The diploma thesis was focused on evaluation of non-thermal (cold) plasma seed treatment of cabbage (Brassica oleracea var. capitata), on its health and production properties and on the effects against Xanthomonas campestris pv. campestris (Xcc). A soil fungus Trichoderma virens (TVI) was used as additional seed treatment. The field experiment showed that microwave, low pressure, 500 W non-thermal plasma and 4 minute exposure time did not have a significant effect on Xcc, but had a positive influence - in combination with Xcc and TVI - on plants´ vitality and yield. Further, this plasma treatment, in combination with Xcc, had a negative impact on seeds´ germination. Non-thermal plasma treatment with the above-mentioned parameters proved to be unsuitable for cabbage seed treatment.